Alex Harper, Dave Bull and Scott Griffin are in their 20's and from Brisbane, they're currently cycling their way through western Queensland on the final leg of their 3,500 kilometre journey from Uluru in the Northern Territory to Brisbane.

Cyclist Alex Harper told ABC's Chrissy Arthur, they're hoping to get people thinking about mental illness by talking at public meetings and fund raising for Australian Rotary Health as they travel through the outback.

"We know that the services aren't great in the country or not as good as the city and this is often where it is really needed out here," he said.

Mr Harper said mental health has become a particular concern for him because he's volunteered for a number of years at Rosies street mission in Brisbane where he's seen 80 to 90 per cent of patrons with some sort of mental illness.

"We're not mental health experts, all we want to do is something a bit silly so people will pay attention.

"It's a really serious issue, one in two Australians in their lifetime will have a mental illness or a mental disorder and we don't talk about it quite as much as we ought to," he explained.

The trio are also members of the Australian Voices choir and they're singing as they cycle to keep their spirits up as they battle head winds along the outback highways.

"At the end of this year we're going to Germany - we're really trying to make the world aware of what's happening in Australian music here," said Mr Harper.